Three separate Deep Ocean Expedition (DOE) trips are already fully booked to set sail from Saint Johns, Newfoundland, catering to 20 paying guests a time and lasting for 12 days each.

It will take a day and a half sailing time to reach the dive site and once there lectures will be given to prepare divers for the rigors of the deep sea.

A Mir submersible chartered from the Russian Academy of Sciences -- one of the only vehicles sturdy and technologically advanced enough to reach such depths -- will then make a series of visits to the wreck site.

"Dives take between 10 and 12 hours to complete," says McCallum.

"It takes two hours to get down and two hours to get back. That gives (at least) six hours down on the wreck looking around," he adds.

Divers are able explore the outer regions of both the bow and stern sections of the fractured vessel -- which are situated three quarters of a mile apart on the ocean floor -- as well as peer into the ship's inner sanctum, says McCallum.

"It is an emotional experience," he says describing the sight of the Titanic first coming into view.

"It is just such a big vessel. There is something about Titanic in terms of her majesty and her grace. She was the pinnacle of human engineering achievement at that time," he adds.

"They are driven by a passion," says McCallum. "Sometimes it's a link to Titanic, to relationships with someone that was on board or in the construction or operation of the vessel."

"Other times there are people of an engineering bent, and occasionally it is not people who are interested in the wreck, they are just interested in getting two and half miles below the surface to see what's there," he adds.

No matter what the individual reasons may be, almost all who make the trip are humbled by what they experience, says McCallum. For them, "To actually see the Titanic and to explore it is the culmination of a dream," he says.

Unless another company comes along with a viable plan to continue the commercial voyages, however, McCallum believes it likely that future generations will be unable to indulge their varying Titanic curiosities first hand.

"If someone wanted to try it, good luck to them," McCallum says.

"Unless you are already substantially invested within deep-water explorations, I find it likely that .... it would be too much of a challenge," he adds.